The principle of obtaining amines starting from an olefin, hydrogen, carbon monoxide and a primary or secondary amine is known. Various techniques embodying this principle have been described using catalysts of various kinds.
In a paper by Iqbal published in Helvetica Chemica Acta, Volume 54, pages 1440 to 1445 (1971), as well as in U.S. Pat. No. 3,947,458 (1976), the catalytic aminomethylation of olefins is described employing a rhodium oxide catalyst, an iron carbonyl catalyst and a mixed rhodium oxide/iron carbonyl catalyst.
U.S. Pat. No. 4,096,150 (1978) discloses a process for the manufacture of tertiary amines wherein an olefin, hydrogen, CO and secondary amine are reacted in the presence of a coordination complex catalyst of a Group VIII metal and a ligand, the donor atom of which is oxygen, nitrogen or sulfur.
Amines can be prepared from a dehydrogenated paraffin feedstock reacted with a nitrogen-containing compound, carbon monoxide and hydrogen in the presence of a rhodium or ruthenium-containing compound. See U.S. Pat. No. 4,179,469.
Yanagi et al. and Imai teach a process for preparing tertiary amines by reacting a long-chain olefin with carbon monoxide, hydrogen and a primary or secondary amine in the presence of a catalyst comprising rhodium and/or ruthenium and Yanagi teaches using a specifically outlined solvent which allows for phase separation. See U.S. Pat. Nos. 4,448,996 and 4,250,115.
In U.S. Pat. No. 4,207,260 (1980) to Imai, tertiary amines are prepared by reacting an aldehyde, hydrogen and a nitrogen-containing compound in the presence of rhodium- or ruthenium-containing catalyst at temperatures in the range of 50.degree.-350.degree. F. and a pressure in the range of 10 to 300 atm.
Another U.S. patent to Imai (U.S. Pat. No. 4,220,764 1980) teaches preparation of tertiary amines by a similar process except the catalyst comprises a rhodium chloride, rather than a rhodium carbonyl.
Van Leeuwen et al. report in an article in the J. Organometallic Chem. 258 (1983) 343-350, that phosphite ligands can be used to stabilize unsaturated rhodium species in order to hydroformylate otherwise unreactive olefins under mild conditions. No ruthenium carbonyl is employed in this process.
In J. Org. Chem., 47, 445 (1982), Jachimowicz, et al. discuss the various approaches which have been used to attempt to devise a one-step, efficient and general conversion of olefins to amines. Among the catalysts used in processes devised by various people have been iron pentacarbonyl, rhodium oxide, ruthenium/iron carbonyl and iridium catalysts. The discussion in this article examines the properties of various aminomethylation catalysts.
In U.S. Pat. No. 4,297,481, Jachimowicz discloses a process for forming a polymeric polyamine/amide wherein said amino/amido nitrogens are positioned in the polymer backbone by contacting a monomeric nitrogen compound which has at least two labile hydrogens bonded to the nitrogen atoms therein, a monomeric hydrocarbon compound containing at least two olefinic groups therein, carbon monoxide and water in the presence of a catalytic amount of a rhodium-containing compound. This invention describes the use of ammonia or primary amines. The preparation of polymers with pendant amine and amide groups is described in U.S. Pat. No. 4,312,965. These polymers are prepared from polymeric polyolefins, carbon monoxide, and monomeric nitrogen compounds as described previously. Again, rhodium or a rhodium-containing compound serves as the catalyst.
Recently issued U.S. Pat. No. 4,503,217 teaches a process for preparing polymeric polyamines from polybutadiene, ammonia and primary or secondary amines in the presence of a catalyst system comprising a ruthenium-containing catalyst and a dimethyl formamide solvent which provides a two-phase liquid product, allowing for easy separation of the product polyamine.
Applicant's pending U.S. application Ser. No. 06/550,347 teaches a process for preparing secondary and tertiary aralkyl amines from aromatic vinylic olefins synthesis gas and a nitrogen-containing compound in the presence of a catalyst system comprising a ruthenium-containing compound, preferably in the presence of an amide solvent.
In the processes discussed above, the selective production of a dialkylaminomethylated internal olefin polymer is not contemplated.
A review of prior art indicates that others have prepared similar materials such as polymeric polyamines. Specifically, poly(butadienes) having high vinyl content that comprise a high concentration of the 1,2-polybutadiene building block have been reacted with synthesis gas and secondary dialkylamines to provide dialkylaminomethylated polymers with a high degree of functionality. Others have formed similar materials but have been unable to functionalize the internal olefinic groups prevalent in lower cost polybutadienes that comprise in the main the 1,4-polybutadiene building block. A good method is not available for causing a reaction to occur in the internal olefin groups prevalent in lower cost polybutadiene. Very often these internal double bonds have remained in the final product, or have been hydrogenated.
Ruthenium carbonyl has been found an excellent catalyst for dialkylaminomethylation of pendant vinyl groups in polybutadiene, for example. Ruthenium-rhodium catalysts have been used to increase reaction rates, but haye often caused gelled polymers for many who have worked in this area.
It would be a considerable advance in the art to devise a system for selectively producing dialkylaminomethylated internal olefin polymers from CO, hydrogen, low cost polymeric olefins such as the 1,4-polybutadiene and secondary amines by an aminomethylation process which results in a product with a high percentage of dialkylaminomethylated polymers. The feasibility of using relatively inexpensive, 1,4-polybutadiene feedstock would represent as much as a 50% decrease in raw material cost for producing these dialkylaminomethylated polymers, but less expensive 1,4-polybutadienes have more internal double bonds.
It would be an advance in the art to devise a catalyst system which causes not only vinyl but internal olefin groups to react. The resulting high amine content polymers with higher functionality should have greater water solubility and be very useful as down hole corrosion inhibitors. In addition, it would be an advance over prior art to devise a process with good conversion of polymeric internal olefins and selectivity to the corresponding dialkylaminomethylated polymers.